What type of signal is required to indicate the operating status of manifolds for gas cylinders?

The correct answer pertains to the local signal required to indicate the operating status of manifolds for gas cylinders. A local signal provides immediate, on-site feedback regarding the operational state of the manifold's system. This typically includes indicators such as lights or alarms that can alert personnel about the status—whether the system is operational, in standby, or has encountered a fault.

Local signals are crucial within the context of medical gas installations, as they ensure that staff can quickly assess the condition of the gas supply without having to consult additional systems or remote displays. The information conveyed by local signals is vital for maintaining safety, as it allows for timely responses to any issues that may arise with the gas supply, thereby ensuring continuous and reliable service in a clinical environment.

Other signal types, while important in other contexts, do not serve the same immediate role at the source of operations.